Optical device and method of manufacture thereof, and electronic instrument

ABSTRACT

An optical device having an optical element, a substrate, and a flexible member. A first portion of the flexible member is disposed spaced apart from the substrate, a second portion surrounding the first portion is adhered to the substrate, and a closed space is formed between the first portion and the substrate. The optical element is mounted on the substrate within the closed space.

[0001] Japanese Patent Application No. 2000-342907, filed on Nov. 10,2000, is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to an optical device and method ofmanufacture thereof and to an electronic instrument.

[0004] 2. Description of Related Art

[0005] An optical device having an optical element such as a solid stateimaging element is known. In the packaging of a conventional opticaldevice, the optical element is contained within a container, and ahermetic seal or the like is applied, so that the optical element is notexposed to moisture. In this way, a conventional optical device has anexpensive container to which a hermetic seal or the like is applied, andtherefore tends to have a high cost.

SUMMARY OF THE INVENTION

[0006] An optical device of the present invention comprises:

[0007] a substrate;

[0008] a flexible member having a first portion disposed spaced apartfrom the substrate, and a second portion surrounding the first portionand adhered to the substrate, in which a closed space is formed betweenthe first portion and the substrate; and

[0009] an optical element within the closed space, and mounted on thesubstrate.

[0010] An electronic instrument of the present invention has the abovedescribed optical device.

[0011] A method of manufacturing an optical device of the presentinvention comprises: mounting an optical element on a substrate;adhering a flexible member to the substrate so as to cover the opticalelement, to form a closed space between the substrate and the flexiblemember; and evacuating the closed space.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 shows a first embodiment of the optical device of thepresent invention.

[0013]FIG. 2 shows a second embodiment of the optical device of thepresent invention.

[0014]FIG. 3 shows a third embodiment of the optical device of thepresent invention.

[0015]FIG. 4 shows a fourth embodiment of the optical device of thepresent invention.

[0016]FIG. 5 shows a fifth embodiment of the optical device of thepresent invention.

[0017]FIG. 6 shows a sixth embodiment of the optical device of thepresent invention.

[0018]FIG. 7 shows a seventh embodiment of the optical device of thepresent invention.

[0019]FIG. 8 shows an electronic instrument having the optical deviceaccording to the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The embodiments of the present invention solve the existingproblems, and have as their object the provision of an optical device ofa simple construction such as to be of low cost and allowing a seal, anda method of manufacture thereof and an electronic instrument.

[0021] (1) An optical device according to the embodiment of the presentinvention comprises:

[0022] a substrate;

[0023] a flexible member having a first portion disposed spaced apartfrom the substrate, and a second portion surrounding the first portionand adhered to the substrate, in which a closed space is formed betweenthe first portion and the substrate; and

[0024] an optical element within the closed space, and mounted on thesubstrate.

[0025] According to the embodiment of the present invention, since thesecond portion of the flexible member is simply adhered to thesubstrate, no container is required, and the optical element can besimply sealed in.

[0026] (2) In this optical device, at least a part of the substrate mayhave light transmissivity.

[0027] (3) In this optical device, the optical element may be mounted onthe substrate, with an optical portion of the optical element opposing apart of the substrate having light transmissivity.

[0028] (4) In this optical device, the flexible member may have a metalfoil and an adhesive layer adhered to the substrate.

[0029] This makes it possible to obtain an optical device of excellentmoisture resistance, noise resistance, and thermal dispersion.

[0030] (5) In this optical device, the flexible member may have a waterrepellent layer on a surface opposite to the side of the closed space.

[0031] This makes it possible to improve the moisture resistance.

[0032] (6) In this optical device, the closed space may be filled withan inert gas.

[0033] The inert gas can protect the optical element.

[0034] (7) In this optical device, a pressure in the closed space may becloser to a pressure in a vacuum than atmospheric pressure.

[0035] Since the optical element is in a state close to a vacuum, it isnot exposed to moisture.

[0036] (8) In this optical device, the substrate may have a hole openingto the closed space and blocked at a surface opposite to the side of theclosed space.

[0037] This configuration makes it possible to utilize the hole forfilling the closed space with inert gas or for evacuation.

[0038] (9) In this optical device, the hole formed in the substrate maybe blocked by a valve.

[0039] The valve can be used to maintain the inert gas within the closedspace or a state close to a vacuum.

[0040] (10) In this optical device, the hole formed in the substrate maybe blocked by resin.

[0041] The resin can be used to maintain the inert gas within the closedspace or a state close to a vacuum.

[0042] (11) In this optical device, the substrate may have a holeblocked on a surface on the side of the closed space by the flexiblemember, and opening on a surface opposite to the side of the closedspace.

[0043] The flexible member can be used to maintain the inert gas withinthe closed space or a state close to a vacuum.

[0044] (12) In this optical device, the closed space may be filled withtransparent resin.

[0045] The transparent resin can protect the optical element.

[0046] (13) In this optical device, the substrate may have a penetratinghole filled with transparent resin.

[0047] The transparent resin can be used to maintain the inert gaswithin the closed space or a state close to a vacuum.

[0048] (14) An electronic instrument according to the embodiment of thepresent invention comprises the above described optical device.

[0049] (15) A method of manufacturing an optical device according to theembodiment of the present invention comprises: mounting an opticalelement on a substrate; adhering a flexible member to the substrate soas to cover the optical element, to form a closed space between thesubstrate and the flexible member; and evacuating the closed space.

[0050] According to the embodiment of the present invention, since theflexible member is simply adhered to the substrate to evacuate theclosed space, no container is required, and the optical element can besimply sealed in.

[0051] (16) In this method of manufacturing an optical device,evacuation may be carried out through a penetrating hole formed in thesubstrate, and the hole may be then blocked by resin.

[0052] The resin can maintain a state close to a vacuum within theclosed space.

[0053] (17) In this method of manufacturing an optical device,evacuation may be carried out through a penetrating hole formed in thesubstrate, and the hole may be then blocked by a valve.

[0054] The valve can maintain a state close to a vacuum within theclosed space.

[0055] (18) In this method of manufacturing an optical device,evacuation may be carried out through a penetrating hole formed in thesubstrate, and the hole maybe then blockedby the flexible member.

[0056] The flexible member can maintain a state close to a vacuum withinthe closed space.

[0057] (19) This method of manufacturing an optical device may furthercomprise:

[0058] filling the closed space with transparent resin,

[0059] wherein evacuation may be carried out through a penetrating holeformed in the substrate, and the hole may be then blocked by thetransparent resin.

[0060] The transparent resin can maintain a state close to a vacuumwithin the closed space.

[0061] The embodiments of the present invention will be described withreference to the drawings.

[0062] First Embodiment

[0063]FIG. 1 shows the first embodiment of the optical device of thepresent invention. The optical device has at least one (one or aplurality) optical element 10. The optical element 10 has an opticalportion 12. The optical element 10 may equally be a photoreceptorelement or a photoemitter element. When the optical element 10 is aphotoemitter element, the optical portion 12 is a light-emittingportion, and when the optical element 10 is a photoreceptor element, theoptical portion 12 is a light-receiving portion.

[0064] In this embodiment, the optical element 10 is an imaging element(image sensor). If it is a two-dimensional image sensor, a plurality ofphotoreceptors (for example, photodiodes) constituting a plurality ofpixels forms the optical portion 12. If it is a CCD (Charge CoupledDevice) type of imaging element, it has a transfer section not shown inthe drawings, and the electric charge from the photoreceptor for eachpixels is transferred at high speed. As a variant example different fromthis embodiment, the optical element 10 may be a surface photoemitterelement, and in particular a surface emission laser. A surfacephotoemitter element such as a surface emission laser emits light in thedirection perpendicular to the substrate on which the element isconstituted.

[0065] In order to provide electrical connection with the exterior, theoptical element 10 may have one or more (in this embodiment a plurality)bumps 14. For example, on the surface on which the optical portion 12 isformed, bumps 14 may be provided to accomplish electrical connection ofthe optical element 10 with the exterior. The bumps 14 are provided inpositions to allow electrical connection with other elements. The bumps14 preferably project beyond the optical portion 12.

[0066] The optical device has a substrate 20. At least a part of thesubstrate 20 (a part allowing light to pass to the optical element 10)has light transmissivity. The substrate 20 shown in FIG. 1 has lighttransmissivity overall, and is for example a glass substrate. On thesubstrate 20 an interconnecting pattern 22 is formed. Theinterconnecting pattern 22 may have lands formed as regions bonded tothe optical element 10 or the like. Provided that the electricalconnection is not interfered with, the interconnecting pattern 22 ispreferably covered with another element (for example, a resist or thelike not shown in the drawings). The interconnecting pattern 22 shown inFIG. 1 is formed on one surface of the substrate 20 only, but may beformed on both surfaces of the substrate 20 and electrically connectedby through holes (not shown in the drawings) or the like.

[0067] The optical element 10 is mounted on the substrate 20 with theoptical portion 12 facing the substrate 20 (more precisely a portionhaving light transmissivity thereof). That is to say, the opticalelement 10 is mounted on the substrate 20 to form a face-downconstruction. The bumps 14 of the optical element 10 and theinterconnecting pattern 22 are bonded. If necessary, the optical element10 and interconnecting pattern 22 may be electrically connected by wiresnot shown in the drawings. In this embodiment, on the substrate 20, inaddition to the optical element 10, electronic components 24 and 26 aremounted.

[0068] The optical device has a flexible member 30. As the flexiblemember 30 can be used tape or sheet form. The flexible member 30 maycomprise multiple layers. The flexible member 30 shown in FIG. 1 has abase layer 34 and an adhesive layer 36. The base layer 34 may have atleast one of the properties of not allowing moisture to pass (or havinghigh resistance to moisture), of not allowing magnetism to pass, and ofhaving high thermal dispersion. By means of this, an optical device ofhigh moisture resistance, noise resistance, and thermal dispersion isobtained. The base layer 34 may be opaque, enabling light to beprevented from entering the optical element 10. By means of this, anoptical device of low light-induced misoperation is obtained. If thebase layer 34 is a metal foil of aluminum, copper, or the like, theserequirements can be satisfied. The adhesive layer 36 is formed of anadhesive such as an epoxy resin, an acrylic resin, a silicone resin, orthe like. The adhesive layer 36 may be provided over the entire area ofthe base layer 34, or may be provided only in a part (for example, thesecond portion 32 described below).

[0069] A first portion 31 of the flexible member 30 is disposed spacedapart from the substrate 20. The first portion 31 is a portion of theflexible member 30 excluding the extremity (for example, the centerportion). A region surrounded by the second portion 32 (for example, theextremity) is the first portion 31. The flexible member 30 has thesecond portion 32 (for example, the extremity) which surrounds the firstportion 31 adhered to the substrate 20. The adhesive layer 36 can bedisposed on the substrate 20, and the flexible member 30 and thesubstrate 20 adhered by the adhesive layer 36. In this case, theadhesive layer 36 is an inner layer, and the base layer 34 is an outerlayer.

[0070] Between the first portion 31 and the substrate 20 is formed aclosed space 40. The first portion 31 and the substrate 20 arepreferably in intimate contact in order to maintain the closed space 40airtight. The optical element 10 is provided within the closed space 40.In more detail, surrounding the optical element 10 the first portion 31is adhered to the substrate 20, and the second portion 32 covers theoptical element 10. Within the closed space 40, it is preferable formoisture to be low. For example, the closed space 40 may contain avacuum (Strictly speaking, a state closer to a vacuum than atmosphericpressure. The same applies subsequently.), or may be filled with aninert gas (N₂ or the like). In these environments, the optical element10 is protected so as not to be exposed to moisture. According to thisembodiment, the optical element 10 can be sealed with a simpleconstruction.

[0071] In this embodiment of the optical device, the optical element 10is a photoreceptor element, and light which has passed through thesubstrate 20 impinges on the optical element 10. Alternatively, as avariant example, if the optical element 10 is a photoemitter element,light emitted from the optical element 10 passes through the substrate20 and is output.

[0072] This embodiment of the optical device is constructed as describedabove, and the method of manufacture thereof is now described. In thisembodiment, the optical element 10 is mounted on the substrate 20, andthe flexible member 30 is adhered to the substrate 20 so as to cover theoptical element 10. In more detail, the optical element 10 is covered bythe first portion 31 of the flexible member 30, and the second portion32 surrounding this is adhered to the substrate 20. For the adhesion ofthe flexible member 30 and the substrate 20, an adhesive may be used.For example, the flexible member 30 may be previously provided with theadhesive. In this embodiment, by means of the adhesive layer 36 of theflexible member 30, the flexible member 30 (second portion 32) and thesubstrate 20 are adhered.

[0073] Then, the closed space 40 is formed between the substrate 20 andthe flexible member 30. If the flexible member 30 is adhered to thesubstrate 20 in a vacuum, within the closed space 40 will be a vacuum.If the flexible member 30 is adhered to the substrate 20 in anenvironment filled with an inert gas, within the within the closed space40 can be filled with an inert gas. The optical element 10 is sealed andprotected within the closed space 40. According to this embodiment, theoptical element 10 can be sealed by a simple process.

[0074] The present invention is not limited to the above describedembodiment, and various variants are possible. Other embodiments are nowdescribed.

[0075] Second Embodiment

[0076]FIG. 2 shows the second embodiment of the optical device of thepresent invention. This embodiment differs from the first embodiment inthat a flexible member 50 has a water repellent layer 52. The waterrepellent layer 52 is formed on the opposite surface of a base layer 54from the surface on which an adhesive layer 56 is formed. As the waterrepellent layer 52 may be cited a fluorine coating. The water repellentlayer 52 forms a protective film, and improves the moisture resistanceof the optical device. The water repellent layer 52 may be such as to beable to be melted by a laser. In this case, marking is possible.

[0077] In respect of the remaining construction, the effect, and themethod of manufacture, this embodiment corresponds to the description ofthe first embodiment.

[0078] Third Embodiment

[0079]FIG. 3 shows the third embodiment of the optical device of thepresent invention. This embodiment differs from the first embodiment inthat the closed space 40 is filled with transparent resin 60. Thetransparent resin 60 is provided over the optical portion 12 of theoptical element 10. The transparent resin 60 need only transmit light tothe extent to allow the input of light to the optical element 10 (or theoutput of light from the optical element 10). By means of this, theoptical element 10 is protected by the transparent resin 60. In respectof the remaining construction, the effect, and the method ofmanufacture, this embodiment corresponds to the description of the firstembodiment.

[0080] Fourth Embodiment

[0081]FIG. 4 shows the fourth embodiment of the optical device of thepresent invention. This embodiment differs from the first embodiment inthat a hole 72 is formed in a substrate 70. The hole 72 passes throughthe substrate 70, and opens in the closed space 40. The hole 72 isblocked. To block the hole 72, resin 74 may be provided. The resin 74may be provided on the opposite side of the substrate 70 from the closedspace 40. The resin 74 may penetrate the hole 72.

[0082] In this embodiment, the closed space 40 contains a vacuum(strictly speaking, a state closer to a vacuum than atmosphericpressure). For example, by means of the hole 72, the closed space 40 canbe connected to the exterior, and a vacuum created, whereby the closedspace 40 contains a vacuum, then the hole 72 may be blocked by the resin74 or the like. By means of this, the closed space 40 can be evacuatedsimply. In respect of the remaining construction, the effect, and themethod of manufacture, this embodiment corresponds to the description ofthe first embodiment.

[0083] Fifth Embodiment

[0084]FIG. 5 shows the fifth embodiment of the optical device of thepresent invention. In this embodiment, the hole 72 is formed in thesubstrate 70 (in detail, as described in the fourth embodiment), and theclosed space 40 is filled with transparent resin 60 (in detail, asdescribed in the third embodiment). The transparent resin 60 is alsoprovided in the hole 72, and by means of this the hole 72 is blocked.

[0085] After previously evacuating the closed space 40, the closed space40 may be filled with the transparent resin 60 through the hole 72.Alternatively, the transparent resin 60 may be provided to seal theoptical element 10, and after adhering the flexible member 30, the foamwithin the closed space 40 may be removed through the hole 72.

[0086] In respect of the remaining construction, the effect, and themethod of manufacture, this embodiment corresponds to the description ofthe first, third, and fourth embodiments.

[0087] Sixth Embodiment

[0088]FIG. 6 shows the sixth embodiment of the optical device of thepresent invention. In this embodiment, the hole 72 is formed in thesubstrate 70 (in detail, as described in the fourth embodiment), and thehole 72 is blocked by the flexible member 30. In more detail, the hole72 is blocked on the surface of the substrate 70 opposite to the closedspace 40. The portion of the flexible member 30 blocking the hole 72 isthe portion adhered to the substrate 70. The hole 72 may be left open onthe surface of the substrate 70 opposite to that of the closed space 40,or this may be filled with resin or the like, or may be used as a holefor attachment to another element, or for positioning.

[0089] In the method of manufacture of this embodiment of the opticaldevice, the flexible member 30 is first adhered to the substrate 70 soas not to block the hole 72. Through the hole 72, the closed space 40 isevacuated, and the flexible member 30 is pulled in the direction of theclosed space 40, to obtain this embodiment. By means of this, by mereevacuation, the hole 72 can be blocked. In respect of the remainingconstruction, the effect, and the method of manufacture, this embodimentcorresponds to the description of the first and fourth embodiments.

[0090] Seventh Embodiment

[0091]FIG. 7 shows the seventh embodiment of the optical device of thepresent invention. In this embodiment, the hole 72 is formed in thesubstrate 70 (in detail, as described in the fourth embodiment), and thehole 72 is blocked by a valve 80. The valve 80 is provided, for example,on the surface of the substrate 70 opposite to that of the closed space40. The valve 80 may be a film. The valve 80 is opened, the closed space40 is evacuated through the hole 72, and the hole 72 is blocked by thevalve 80. In respect of the remaining construction, the effect, and themethod of manufacture, this embodiment corresponds to the description ofthe first and fourth embodiments.

[0092] It should be noted that FIG. 8 shows a digital camera 100, as anexample of an embodiment of an electronic instrument to which thepresent invention is applied. The digital camera 100 has the abovedescribed optical device.

What is claimed is:
 1. An optical device comprising: a substrate; aflexible member having a first portion disposed spaced apart from thesubstrate, and a second portion surrounding the first portion andadhered to the substrate, in which a closed space is formed between thefirst portion and the substrate; and an optical element within theclosed space, and mounted on the substrate.
 2. The optical device asdefined in claim 1, wherein at least a part of the substrate has lighttransmissivity.
 3. The optical device as defined in claim 2, wherein theoptical element is mounted on the substrate, with an optical portion ofthe optical element opposing a part of the substrate having lighttransmissivity.
 4. The optical device as defined in claim 1, wherein theflexible member has a metal foil and an adhesive layer adhered to thesubstrate.
 5. The optical device as defined in claim 1, wherein theflexible member has a water repellent layer on a surface opposite to theside of the closed space.
 6. The optical device as defined in claim 1,wherein the closed space is filled with an inert gas.
 7. The opticaldevice as defined in claim 1, wherein a pressure in the closed space iscloser to a pressure in a vacuum than atmospheric pressure.
 8. Theoptical device as defined in claim 6, wherein the substrate has a holeopening to the closed space and blocked at a surface opposite to theside of the closed space.
 9. The optical device as defined in claim 7,wherein the substrate has a hole opening to the closed space and blockedat a surface opposite to the side of the closed space.
 10. The opticaldevice as defined in claim 8, wherein the hole formed in the substrateis blocked by a valve.
 11. The optical device as defined in claim 9,wherein the hole formed in the substrate is blocked by a valve.
 12. Theoptical device as defined in claim 8, wherein the hole formed in thesubstrate is blocked by resin.
 13. The optical device as defined inclaim 9, wherein the hole formed in the substrate is blocked by resin.14. The optical device as defined in claim 6, wherein the substrate hasa hole blocked on a surface on the side of the closed space by theflexible member, and opening on a surface opposite to the side of theclosed space.
 15. The optical device as defined in claim 7, wherein thesubstrate has a hole blocked on a surface on the side of the closedspace by the flexible member, and opening on a surface opposite to theside of the closed space.
 16. The optical device as defined in claim 1,wherein the closed space is filled with transparent resin.
 17. Theoptical device as defined in claim 16, wherein the substrate has apenetrating hole filled with transparent resin.
 18. An electronicinstrument comprising the optical device as defined in claim
 1. 19. Amethod of manufacturing an optical device comprising: mounting anoptical element on a substrate; adhering a flexible member to thesubstrate so as to cover the optical element, to form a closed spacebetween the substrate and the flexible member; and evacuating the closedspace.
 20. The method of manufacturing an optical device as defined inclaim 19, wherein evacuation is carried out through a penetrating holeformed in the substrate, and the hole is then blocked by resin.
 21. Themethod of manufacturing an optical device as defined in claim 19,wherein evacuation is carried out through a penetrating hole formed inthe substrate, and the hole is then blocked by a valve.
 22. The methodof manufacturing an optical device as defined in claim 19, whereinevacuation is carried out through a penetrating hole formed in thesubstrate, and the hole is then blocked by the flexible member.
 23. Themethod of manufacturing an optical device as defined in claim 19,further comprising: filling the closed space with transparent resin,wherein evacuation is carried out through a penetrating hole formed inthe substrate, and the hole is then blocked by the transparent resin.